By 1860 the number of miles of railroad tracks throughout the United States had risen to

By 1860, 30,000 miles (49,000 km) of railroad tracks had been laid,.

By 1860, 30,000 miles (49,000 km) of railroad tracks had been laid, with 21,300 miles (34,000 km) concentrated in the northeast.

b) the importance and limits of political power.

1st amendment: freedom of speech, religion, petition, press, and assembly

2nd: right to bear arms

3rd: quartering of soldiers

4th: search and seizure